I will obtain computer solutions of the steady-state fluid and protein transport equations for various multiple "equivalent pore" models of the microvascular membrane of the lung. I will use steady- state hydrostatic presspure, protein concentration and lymph flow data obtained in unanesthetized chronically-instrumented sheep. I will do new experiments using up to four simultaneous molecular probes to refine the limits of membrane pore structure. I will evaluate the sensitivity of the model to some of the simplifying assumptions; especially whether changes in interstitial fluid pressure affect and model predictions and whether vesicular (non-hydraulic) transport could account for any of the observed results. My actual involvement with experimental methodology and data acquisition, together with the computer simulation work will greatly enhance my future capabilities in the area of bioengineering as applied to problems of pulmonary physiology and disease.